I am eligible for a new 3GS with a new contract. Is it possible for me to buy the phone, sign the contract, put my sim in the new phone and then take it out and put it back into my old one? After that i'd give the new one to a friend who has a JBed/Unlocked 2G as a Christmas Present. They would use the 3GS with their sim, no data plan. All the time I will continue to use my iPhone 3G with a new 2 year data plan agreement on it. Is this possible? Sorry, just wondering-thanks!